Related Clues:

• Jekyll, vis-à-vis Hyde
• 19-Down, for one
• Rabid enthusiast
• Intimate confidante
• Ardent fan
• Change conceit for other self
• Hidden or second self- in Latin
• One's other self
• Go, relate to other self
• Hidden self or very close friend
• To regale other self
• Hidden or second self - in Latin
• One's second self
• 'One's second self (5,3)'
• 'One's alternative personality (5,3)'